Racks, magazines, rails or bays are known for storing medium-caliber ammunition for armored-vehicle turrets in which the storage takes place on a single or dual turntable often located at the rear of the turret while the guiding, pulling and conveyance of the ammunition is achieved between this or these turntable(s) and the barrel generally situated at the front of the turret, passing through various specific guiding, pulling and/or conveying structures such as conveyors and ratchet boxes. The passage of the medium-caliber ammunition between the rack and its conveying structures and the barrel can occur through hoses.
It is, however, desirable to maximize the space inside the turret and improve the overall ergonomics thereof, for example by:                minimizing the size of the structures for storing the medium-caliber ammunition by placing one or several turntable(s), also called feeder(s), located at the rear of the turret;        reducing the guiding, pulling and/or conveying forces for the medium-caliber ammunition during the transfer thereof from the feeder(s) to the barrel via a completely mechanical system by providing a set of specific and consecutive structural guiding elements such as a conveyor, a ratchet box, or both;        facilitating the (re)loading and/or unloading of the medium-caliber ammunition throughout the entire path of the latter when the vehicle is stopped, or possibly in motion.        
It may also be desirable to increase the safety of the occupants of the turret. Thus, high-density polyethylene (HDPE) strips, as used in most bottle or can conveying systems, can be placed along the entire conveyor in order to reduce friction between the structure and the medium-caliber ammunition during the motion of the latter, in other words to decrease the risks of detachment of the strips or chains of medium-caliber ammunition. Furthermore, it is possible to provide a groove in the middle of the conveying path to prevent the deposition of dirt therein, such as crushed stone, dust, etc. liable to ignite the ammunition. Lastly, using a ratchet box, which designates a device containing a ratchet wheel, the curved teeth of which allow to better match the shape of the medium-caliber ammunition and of their link, facilitates the handling of the medium-caliber ammunition up to the barrel, in addition to its role dedicated to the pulled and guided conveyance (see above).
Currently, these needs are met through the use of different types of medium-caliber ammunition racks, where the ammunition is stored either vertically or horizontally. These operate with or without any electricity supply, given that the feeder(s), whether stationary or rotating, is (are) located either directly next to the barrel, or at the rear of the turret.
More specifically, three types of solutions exist in the state of the art:                ammunition racks with two feeders have catching and winding specificities providing a spiral path for the ammunition arranged vertically, ideally with no friction between pieces of ammunition, the whole being controlled by a mechanism based on a specific brake. This approach shows a device that is generally located very close to the barrel, that does not have any structural intermediary aside from the aforementioned hoses, and in which the two feeders are located on either side of the barrel;        ammunition racks presenting pieces of ammunition positioned vertically in a spiral or serpentine path and pulled via a motorized conveyor belt, from the feeder(s) located at the rear of the turret, to the barrel. This conveyance occurs through various structural elements, such as a ratchet box, a conveyor, etc., either on the same side of the barrel, or on either side thereof;        ammunition racks in which the pieces of ammunition are stored horizontally in the rack itself and arranged along a path with successive turns. Each stage will bring the pieces of ammunition to a different hose, such that the selection will occur at the level of the barrel. In this configuration, the medium-caliber ammunition can also be driven from the magazine to the barrel using a ratchet box.        
These different types of ammunition racks are in particular described in the following documents: EP0754926, US2014096671, WO2014035032, CN201837306, WO2011155971, EP1749179, US2012227300, WO2013087053, US2012117840, CN101660886, US2007107592, US2006249131, EP1612502, U.S. Pat. Nos. 5,905,224, 5,561,258, DE3838758, EP0290031, U.S. Pat. No. 4,601,230, EP0210713, U.S. Pat. No. 4,332,097, EP 1589312, EP0272399, US2012/0024144, EP0361050, U.S. Pat. No. 4,674,392, US20090120271, DE4206644, U.S. Pat. No. 8,485,083.
Most of these prior-art solutions require significant pulling forces due to the friction generally present between the structure and the medium-caliber ammunition, often making it necessary to add a motor in order to pull the medium-caliber ammunition toward the barrel, especially when the magazines are away from the barrel and/or produce a significant bulk within the turret, which may reduce the storage capacity of the magazine(s). Lastly, the mechanical complexity of these devices increases the manufacturing time and production cost thereof.